JP6551788B2 - Drive transmission device and image forming apparatus - Google Patents

Description

  The present invention relates to a drive transmission device and an image forming apparatus.

  There is known a drive transmission device including a connecting member that connects a first rotating body and a second rotating body.

  Patent Document 1 describes a drive transmission device including the following connecting member as the connecting member. A cylindrical connection that connects the first insertion portion inserted into the hole at the rotation center of the first rotating body, the second insertion portion inserted into the recess of the second rotating body, and the first and second insertion portions. And a connecting member. The first insertion portion includes a spherical portion and a first protrusion that protrudes in the radial direction from the outer peripheral surface of the spherical portion. The second insertion portion includes a spherical portion and a second protrusion that protrudes in the radial direction from the outer peripheral surface of the spherical portion. Two first protrusions of the first insertion portion are provided with an interval of 180 ° in the rotation direction, and an interval of 180 ° is provided in the rotation direction on the inner peripheral surface of the hole portion of the first rotation body. Engaging with the provided axially extending first groove. Further, two second protrusions of the second insertion portion are provided at an interval of 180 ° in the rotational direction, and are spaced at an interval of 180 ° in the rotational direction on the inner peripheral surface of the recess of the second rotary body. It engages with a second axially extending groove provided. The drive transmission device is also provided with a regulating member that regulates the first insertion portion of the connecting member from coming out of the hole of the first rotating body.

  In addition, the applicant is developing a drive transmission apparatus having the following configuration. That is, the first groove portion is stopped halfway without extending to the second rotary body side end of the first rotary body. As a result, the first projection abuts against the second rotary body side end of the first groove and prevents the first insertion portion from coming out of the hole of the first rotary body. In addition, the guide groove extending in the axial direction from the opening has an opening into which the first protrusion is inserted at a position different from the first groove portion forming position at the second rotating body side end portion of the hole portion. Is formed in the hole of the first rotating body. Moreover, the communication part which makes a guide groove and a 1st groove part connect is provided inside the hole part.

  When inserting the first insertion portion into the hole of the first rotating body, first, a coil spring is inserted into the hole of the first rotating body. Next, the spherical portion of the first insertion portion is inserted into the hole portion of the first rotary body by aligning the rotational direction of the guide groove and the first protrusion so that the first protrusion is inserted into the guide groove. To do. Then, the first protrusion is inserted into the guide groove. Next, the first insertion portion is pushed into the first hole against the biasing force of the coil spring. Next, when the first protrusion reaches the communicating portion, the connecting member is rotated. Then, the first protrusion moves from the guide groove to the first groove through the communication portion, and the first protrusion is positioned in the first groove. Thus, when the first protrusion is positioned in the first groove, the hand is released from the connecting member. Then, the connecting member moves to the second rotating body side by the urging force of the coil spring, and the first projecting portion is positioned on the second rotating side with respect to the communication portion of the first groove portion with the guide groove. Thereby, the connecting member is assembled to the first rotating body.

  By moving the second rotating body in the axial direction, the second insertion portion of the connecting member is inserted into the recess of the second rotating body, and the second rotating body is assembled to the connecting member. At this time, when the second insertion portion is not inserted into the concave portion of the second rotating body because the phase in the rotational direction of the second groove portion and the second protrusion is not matched, the connecting member is pushed in by the second rotating body, The first insertion portion moves in the hole of the first rotating body while compressing the coil spring. Thereby, even if the 2nd insertion part is not inserted in the recessed part of a 2nd rotary body, a 2nd rotary body can be located in the predetermined position in an apparatus. Then, when the coupling member or the second rotating body is rotationally driven during the drive transmission, the phases of the second projection and the second groove are aligned. Then, the connecting member moves to the second rotating body side by the urging force of the coil spring, the second protrusion enters the second groove, and the second insertion part enters the recess of the second rotating body. Thus, the second rotating body is assembled to the connecting member, and the driving force is transmitted between the connecting member and the second rotating body.

  In recent years, there has been an increasing demand for miniaturization of the device, and there is a demand for arranging the second rotating body as close as possible to the first rotating body in the axial direction, and it is necessary to shorten the connecting member. However, in the drive transmission device under development, the connecting member can not be made sufficiently short.

  In order to solve the above problems, the present invention relates to a first rotating body having a hole at the center of rotation, a second rotating body having a hole at the center of rotation, and an inner peripheral surface of the hole of the first rotating body. A first groove portion extending in the axial direction provided on the inner surface, a second groove portion extending in the axial direction provided on an inner peripheral surface of the hole portion of the second rotating body, and a radial protrusion engaging with the first groove portion. A first insertion portion that is inserted into the hole of the first rotating body, a second projection portion that protrudes in the radial direction and engages with the second groove portion, A second insertion portion that is inserted into the hole of the rotating body, and a connecting portion that connects the first inserting portion and the second inserting portion, and connects the first rotating body and the second rotating body; A drive transmission device comprising a connecting member, wherein the first insertion portion is movable in the axial direction within the hole of the first rotating body, and the first groove portion is formed. The first projection can be inserted into the hole of the first rotating body at a different position in the rotational direction, and is inserted into the hole at a different position in the rotational direction than the formation position of the first groove. The first protrusion can be positioned in the first groove inside the hole, and after being positioned in the first groove, the first protrusion moves in the first groove toward the second rotating body. The hole portion and the first groove portion of the first rotating body are configured so that the maximum outer diameter of the second insertion portion is smaller than the inner diameter of the hole portion of the first rotating body. It is.

  According to the present invention, the connection member can be assembled to the first rotating body even if the length of the connection member is shortened.

FIG. 1 is a schematic configuration view showing an example of an electrophotographic image forming apparatus according to an embodiment. The disassembled perspective view of a drive transmission apparatus. Sectional drawing of a drive transmission apparatus. The perspective view of a connection member. AA sectional drawing of FIG. The figure which shows the prior art example of lightening of a connection member. The figure which shows the example of shaping | molding of the connection member of this embodiment. FIG. 5 is a perspective view showing a photosensitive gear and a connecting member. FIG. 2 is a cross-sectional perspective view showing a photosensitive gear and a connecting member. The figure explaining the dimensional relationship of a connection member and a drive side cylindrical part. The cross-sectional perspective view which shows a mode that a connection member is rotated and each drive side projection part is moved to a drive side groove part through a communication part. FIG. 7 is a perspective view showing the connecting member attached to the photosensitive gear. The perspective view of a bearing. The cross-sectional perspective view explaining the control by the control projection part of a bearing. The perspective view of a coupling member. Sectional perspective view of a coupling member. The cross-sectional perspective view which shows the state which inserted the driven-side spherical part of the connection member in the driven-side cylindrical part of the coupling member. Sectional drawing which cut the coupling member and the connection member in the direction orthogonal to the protrusion direction of a driven-side projection part. Sectional drawing which cut the coupling member and the connection member in parallel with the protrusion direction of a driven-side projection part. The figure explaining the drive transmission of the conventional connection member and coupling member. The figure which shows the state rotated 90 degrees from the state of FIG. The figure explaining the drive transmission of the connection member and coupling member of this embodiment. The figure which shows the state rotated 90 degrees from the state of FIG. 6 is a graph in which fluctuations in the speed of the photosensitive drum are investigated when the shaft center of the drum shaft is shifted by a predetermined amount with respect to the rotating shaft of the photosensitive gear in a conventional configuration. 6 is a graph in which the fluctuation of the speed of the photosensitive drum is examined when the center of the drum shaft is shifted by a predetermined amount with respect to the rotational axis of the photosensitive gear in the configuration of the present embodiment. The figure which shows the modification of a drive-side projection part and a driven-side projection part.

  Hereinafter, an embodiment of an image forming apparatus to which the present invention is applied will be described. FIG. 1 is a schematic configuration view showing an example of an electrophotographic image forming apparatus according to the embodiment. In FIG. 1, a main body 1 of an image forming apparatus of a tandem type intermediate transfer type is placed on a paper feed table 200 that is a paper feed unit as a recording material supply unit that accommodates and supplies paper that is a recording material. . The subscripts Y, M, C, and K in the figure indicate yellow, magenta, cyan, and black (black) colors, respectively.

  In the vicinity of the center of the main body 1 of the image forming apparatus, an intermediate transfer is an endless belt-like image carrier that is looped around a plurality of support rollers 13, 14, 15, 16, and 63 and can be rotated and conveyed clockwise in the figure. An intermediate transfer belt 10 as a body is provided. In the illustrated example, a cleaning device 17 for the intermediate transfer belt is provided to the left of the secondary transfer counter roller 16 that is one of the support rollers. The cleaning device 17 removes residual toner remaining on the intermediate transfer belt 10 after image transfer. Further, on the intermediate transfer belt 10 stretched between the support roller 14 and the support roller 15, four toner image forming units 18Y, 18M, 18C, and 18K are arranged side by side along the transport direction in tandem. The image forming apparatus 20 is configured.

  On the tandem image forming apparatus 20, as shown in FIG. 1, an exposure device 21 that is an optical writing device as an optical writing unit is provided. The toner image forming units 18Y, 18M, 18C, and 18K of the tandem image forming apparatus 20 are photosensitive drums 40Y, 40M, and 40C as image carriers on which latent images of yellow, magenta, cyan, and black are formed. 40K. The surfaces of the photosensitive drums 40Y, 40M, 40C, and 40K are uniformly charged by the charging devices 60Y, 60M, 60C, and 60K, and then exposed by the exposure device 21 based on the image data. Thus, latent images are formed on the surfaces of the photosensitive drums 40Y, 40M, 40C, and 40K.

  The latent images on the photoconductive drums 40Y, 40M, 40C, and 40K are developed by the developing devices 61Y, 61M, 61C, and 61K, respectively, so that visible images are formed on the surfaces of the photoconductive drums 40Y, 40M, 40C, and 40K, respectively. A toner image of a certain color is carried. In addition, primary transfer rollers 62Y, 62M, 62C, and 62K are provided at primary transfer positions for transferring the toner image from the photosensitive drums 40Y, 40M, 40C, and 40K to the intermediate transfer belt 10. Further, the support roller 14 is a drive roller that rotationally drives the intermediate transfer belt 10. When a black single-color image is formed on the intermediate transfer belt 10, the support rollers 13 and 15 other than the support roller 14 are moved, and the yellow, magenta, and cyan photosensitive drums 40Y, 40M, and 40C are moved to the intermediate transfer belt 10. It is also possible to separate from

  A secondary transfer device 22 is provided on the side opposite to the tandem image forming device 20 with the intermediate transfer belt 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 presses the secondary transfer roller 12 against the secondary transfer opposing roller 16 and applies a transfer electric field to transfer the image on the intermediate transfer belt 10 to the sheet.

  Next to the secondary transfer device 22, a fixing device 25 as a fixing unit for fixing a transferred image on a sheet is provided. The fixing device 25 is configured by pressing a pressure roller 27 as a pressure member against a fixing belt 26 which is an endless belt as a recording material conveying member. Further, the sheet after image transfer is conveyed to the fixing device 25 by a conveying belt 24 which is a recording material conveying member that is wound around the support roller 23 and rotated.

  In the illustrated example, a sheet reversing device 28 is provided under the secondary transfer device 22 and the fixing device 25 in parallel with the above-described tandem image forming device 20 for reversing the sheet to record an image on both sides of the sheet. .

  In the image forming apparatus having the above configuration, when image data is sent to the main body 1 of the image forming apparatus and a signal to start image formation is received, the support roller 14 is rotationally driven by the drive motor to rotate the other support rollers. The intermediate transfer belt 10 is rotated and conveyed. At the same time, single toner images of yellow, magenta, cyan and black are formed on the photosensitive drums 40Y, 40M, 40C and 40K, respectively, by the individual toner image forming units 18Y, 18M, 18C and 18K. Then, along with the conveyance of the intermediate transfer belt 10, these single-color images are sequentially transferred at the primary transfer portions opposed to the primary transfer rollers 62 </ b> Y, 62 </ b> M, 62 </ b> C, and 62 </ b> K to form a composite color image on the intermediate transfer belt 10.

  Further, one of the paper feed rollers 58 of the paper feed table 200 of the paper feed unit is selectively rotated, and a sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43 and separated one by one by the separation roller 45 Into the paper feed path 46. The image is conveyed by the conveyance roller 47 and guided to the paper feed path 48 in the main body 1 of the image forming apparatus, and is abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 50 is rotated to feed the sheet on the manual feed tray 51, and the sheets are separated one by one by the separation roller and put into the manual feed path 53 and similarly hit against the registration roller 49 and stopped. Then, the registration roller 49 is rotated in time with the composite color image on the intermediate transfer belt 10, and the sheet is fed between the intermediate transfer belt 10 and the secondary transfer roller 12 of the secondary transfer device 22 to perform secondary transfer. The apparatus 22 transfers and records a color image on a sheet. The paper after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25. After the transfer image is fixed by applying heat and pressure, the paper is discharged by the discharge roller 56 and is discharged onto the discharge tray 57. Stack to. Alternatively, it is switched by the switching claw and put into the paper reversing device 28, where it is reversed and led again to the secondary transfer position, an image is recorded on the back side, and then discharged onto the discharge tray 57 by the discharge roller 56.

  On the other hand, after the image transfer, the intermediate transfer belt 10 is removed of residual toner remaining on the intermediate transfer belt 10 after image transfer by the cleaning device 17 for the intermediate transfer belt, and image formation by the tandem image forming apparatus 20 is performed again. Prepare.

  In the image forming apparatus having the above-described configuration, a front cover is provided on the front side of the main body 1 (the front side in FIG. 1) by being pivoted with respect to the main body 1 by a support shaft. Then, by rotating the front cover about the support shaft and opening it with respect to the main body 1, the photosensitive drum, the charging device, the developing device, and the cleaning device housed in the main body 1 are combined into one unit. It can be attached and detached. Of the photosensitive drum 40, the charging device, the developing device, and the cleaning device, when there is a component that has reached the end of its life, the unit is removed and replaced with a new unit. Therefore, a drive transmission device that transmits a driving force from a drive motor as a drive source of the image forming apparatus main body to a rotating body that is a target of transmission transmission such as the photosensitive drum 40 is provided with a connecting member that detachably connects the two. It is done.

  In this embodiment, a drive transmission device that transmits drive to the photosensitive drum 40 will be described as an example. However, a drive transmission target is a developing roller, a toner supply screw, and a paper feed table provided in the developing device. Another roller may be used, such as the 200 paper feed roller 58 paper feed roller.

FIG. 2 is an exploded perspective view of the drive transmission device 70, and FIG. 3 is a cross-sectional view of the drive transmission device 70.
The drive transmission device 70 includes a photosensitive member gear 82 serving as a first rotating member to which the driving force is transmitted from the driving motor, a second rotating member coupling member 41 attached to an end of the drum shaft 40 a of the photosensitive member drum, A connecting member 90 for driving and connecting the body gear 82 and the coupling member 41, and a coil spring 73 for urging the connecting member 90 attached to the photosensitive member gear 82 toward the coupling member are provided.

  At the rotational center of the photosensitive gear 82, there is provided a drive side cylindrical portion 82a into which the first insertion portion 90a of the connecting member 90 is inserted. The coupling member 41 includes a cylindrical shaft insertion portion 41a into which the tip end portion of the drum shaft 40a is inserted, and a driven side cylindrical portion 41b into which the second insertion portion 90b of the connecting member 90 is inserted. There is. The shaft insertion portion 41a is provided with a through hole 412 through which a parallel pin 411 provided on the drum shaft 40a passes.

  The connection member 90 includes a first insertion portion 90a, a second insertion portion 90b, and a connection portion 93 that connects the first insertion portion 90a and the second insertion portion 90b. The first insertion portion 90a includes a driving side spherical portion 91, a first driving side protruding portion 94a protruding in a radial direction from the surface of the driving side spherical portion 91, and a second driving side protruding portion 94b. The second drive-side protrusion 94 a is provided at a position 180 ° apart in the rotational direction from the first drive-side protrusion 94 b. The second insertion portion 90 b includes a driven side spherical portion 9 and two driven side projections 95 a that protrude in the radial direction from the surface of the driven side spherical portion 92. The driven protrusions 95a are provided at an interval of 180 ° in the rotational direction.

FIG. 4 is a perspective view of the connecting member 90, and FIG. 5 is a cross-sectional view taken along the line A-A of FIG.
In the following description, the axial direction will be described as the X direction, and the projecting directions of the drive side projection and the driven projection will be described as the Y direction, and a direction orthogonal to both the X direction and the Y direction as the Z direction.
The connection member 90 is a resin molded product, and the first insertion portion 90a, the second insertion portion 90b, and the connection portion 93 are an integral body made of a resin material. As resin used for formation of the connection member 90, polyacetal resin (POM) which is excellent in mechanical strength, and excellent in abrasion resistance and slidability can be used suitably.

  Since the connecting member is molded by injection molding or the like, a sink may occur, and the spherical portions 91 and 92 and the connecting part may be deformed by the sink and the quality may be affected. For this reason, in this embodiment, each spherical part 91,92 and the connection part 93 are thinned, and generation | occurrence | production of sink marks is suppressed.

  The drive side spherical portion 91 of the first insertion portion 90a includes a first drive side great circle portion 91a that is a great circle of a sphere orthogonal to the X direction and a second drive side large circle that is a great circle of a sphere orthogonal to the Z direction. It has a hemispherical shape in which the circular portion 91b and the third driving side large circular portion 91c, which is a large circular sphere orthogonal to the Y direction, are left behind. In addition, the driven-side spherical portion 92 of the second insertion portion 90b is a first driven-side large circle portion 92a which is a large circle of a ball orthogonal to the X direction and a second driven which is a large circle of a ball orthogonal to the Z direction. It has a ball shape which is thin except for the side large circle portion 92b and the third driven side large circle portion 92c which is a large circle of a sphere orthogonal to the Y direction. The great circle is a circle formed by a plane passing through the center of the sphere and the sphere.

  In addition, the connecting portion 93 has a substantially quadrangular prism shape, and a lightening portion 93 a is formed on each side surface of the connecting portion 93. As shown in FIG. 5, the lightening portion 93a is lightened leaving a straight portion extending in the Y direction in the drawing and a straight portion extending in the Z direction in the drawing, and has a cross shape in cross section. The connecting portion is formed such that each side surface is inclined 45 ° with respect to the Y direction. Thus, by forming each side surface to be inclined 45 ° with respect to the Y direction, the straight portion of the lightening portion becomes a diagonal of a quadrangle, and the side surface of the connecting portion is parallel to a plane orthogonal to the Y direction. Compared with the case where it forms so that it may become a field, the straight part of a lightening part can be lengthened. Thereby, the strength reduction of the connection part by lightening can be suppressed.

  The drive side protrusions 94a and 94b of the first insertion portion 90a have a cylindrical shape, and are provided at locations where the first drive side great circle portion 91a and the second drive great circle portion 91b intersect. The height h2 of the first drive side protrusion 94a is higher than the height h1 of the driven side protrusion 95a and the second drive side protrusion 94b. In the present embodiment, the drive-side spherical portion 91 has a shape obtained by removing the hemisphere, but it may be determined appropriately according to the maximum inclination angle of the connecting member 90. In addition, a spring receiver 96 is provided at the rotation center of the drive side spherical portion 91.

  The driven-side projection 95a of the second insertion portion 90b also has a cylindrical shape, and is provided at a location where the first driven large-circle portion 92a and the second driven large-circle portion 92b intersect. The coupling member side of the third driven-side large circular portion 92c of the driven-side spherical portion is closer to the one side in the Z direction (left side in the figure) than the second driven-side large circular portion 92b. And the other side in the Z direction is notched.

FIG. 6 is a view showing a conventional example of lightening of the connecting member 90. As shown in FIG.
As shown in FIG. 6A, when it is intended to suppress the thickness of the connecting member 90 to suppress the sink mark by providing the hole-shaped thinned portion 193 in which the driving side spherical portion 91 side is opened in the connecting member 90. The mold structure is as shown in FIG. That is, the mold structure has a first mold 391 moving in the Y1 direction, a second mold 392 moving in the Y2 direction, and a third mold 393 moving in the X1 direction. In such a case, it is necessary to move the third die 393 forming the long hole-shaped lighted portion 193 in the axial direction largely in the X1 direction in order to pull it out from the molded connecting member. The portion of the third mold 393 in which the hole-shaped lightening portion 193 is formed needs a minimum of 8 mm in diameter due to problems such as strength, and it is difficult to miniaturize the connecting member 90.

  Further, in the conventional configuration in which the hole-shaped thinning portion 193 is provided, in order to satisfactorily pull out the third mold 393 from the molded connecting member, the diameter gradually increases as it goes to the driving side. It is necessary to make the shape of the thin portion 193. As a result, as shown in FIG. 6C, when the connecting member 90 has a shape elongated in the axial direction, the driven-side spherical portion 92 can not be sufficiently thinned, and the thickness t2 of the driven-side spherical portion 92 is increased. The sink of the driven side spherical portion 92 can not be sufficiently suppressed. Therefore, in the configuration shown in FIG. 6, in order to suppress the thickness t2 of the driven-side spherical portion 92, it is necessary to suppress the axial length of the connecting member to 25 mm or less at the longest.

FIG. 7 is a view showing a molding example of the connection member 90 of the present embodiment.
7 (a) is a cross-sectional view showing a molding example of the connecting member 90, FIG. 7 (b) is an AA longitudinal cross-sectional view of FIG. 7 (a), and FIG. 7 (c) is It is a BB longitudinal cross-sectional view of Fig.7 (a). Moreover, FIG.7 (d) is CC longitudinal cross-sectional view of Fig.7 (a).
As shown in FIG. 7 (c), the first metal mold 391 and the second metal mold 392 are formed by forming the lightening portion 93 a into a cross shape having a straight portion extending in the Y direction and a straight portion extending in the Z direction. And can be formed. Further, as shown in FIGS. 7B and 7D, the second large circular portions 91b and 92b and the third large circular portions 91c and 92c of each of the spherical portions 91 and 92 are divided into thin portions of the connecting portion. In the same manner, the first mold 391 and the second mold 392 can be used for molding. As a result, as shown in FIG. 7A, the connecting member 90 can be molded with the first mold 391 moving in the Y1 direction and the second mold 392 moving in the Y2 direction. The connecting member 90 can be molded with a smaller number of molds than the conventional example shown in FIG. Further, the connecting member can be miniaturized as compared with the configuration shown in FIG. Further, even if the axial length of the connecting member is increased, the thickness of the driven side spherical portion, the connecting portion, and the driving side spherical portion can be made uniform. Thereby, even if it makes a connecting member long shape in an axial direction, the precision fall by the influence of sink marks can be controlled.

  In the present embodiment, as shown in FIG. 4 above, the thickness of each large circle of each spherical portion, the thickness of the lightening portion of the connecting portion, and the thickness of the lightening portion as shown in FIG. It is assumed that [mm]. Thereby, the influence of the sink marks of each part can be suppressed, and the connecting member 90 can be molded with high accuracy.

FIG. 8 is a perspective view showing the photosensitive gear 82 and the connecting member 90, and FIG. 9 is a cross-sectional perspective view showing the photosensitive gear 82 and the connecting member 90. As shown in FIG.
The photosensitive gear 82 is a resin molded product made of polyacetal resin (POM), and has a drive side cylindrical portion 82a into which the first insertion portion 90a of the connecting member 90 is inserted at the center of rotation. The driving side tubular portion 82a has a driving side hole 87 into which the driving side spherical portion 91 of the first insertion portion 90a is inserted, and a driving side groove into which the driving side protrusions 94a and 94b of the first insertion portion 90a are inserted. Two parts 85 are provided at an interval of 180 ° in the rotational direction. Further, in the drive side cylindrical portion 82a, the first guide groove 86a for guiding the first drive side protrusion 94a adjacent to the one drive side groove 85 in the rotational direction is rotated to the other drive side groove 85 And a second guide groove 86b that is a phase matching groove that guides the second drive side protrusion 94b adjacent to each other in the direction. One drive groove portion 85 and the first guide groove portion 86a communicate with each other by the communication portion 84 at the back side, and similarly, the other drive groove portion 85 and the second guide groove portion 86b are also connected by the communication portion 84 at the back side. doing.

  As shown in FIG. 8, the groove depth d2 of the first guide groove 86a is longer than the height h2 of the first drive side protrusion 94a. On the other hand, the groove depth d1 of the second guide groove 86b is longer than the height h1 of the second drive side protrusion 94b and shorter than the height h2 of the first drive side protrusion 94a (h1 <d1). <H2 <d2).

  A retaining portion 85 a is provided at the coupling member side end (front side end) of the drive side groove 85, and the connecting member 90 tries to come out of the coupling side end of the drive side hole 87. Then, the drive-side protrusions 94a and 94b abut against the retaining portions 85a. Thereby, the connecting member 90 can be prevented from coming out of the coupling side end of the drive side hole 87.

  Further, as shown in FIG. 9, at the rear end of the drive side cylindrical portion 82a, a control projection 102 for restricting the movement of the drive side projection in the drive side groove of the bearing 100 to the guide groove. An insertion hole 83 is provided in which (see FIG. 3) is inserted.

FIG. 10 is a view for explaining the dimensional relationship between the connecting member 90 and the drive side cylindrical portion 82a.
In the image forming apparatus of the present embodiment, there is a demand to shorten the length of the connecting member 90 as much as possible in order to reduce the size of the apparatus in the axial direction. Therefore, in the present embodiment, as shown in FIG. 10B, the maximum outer diameter R1 of the second insertion portion 90b in the rotational direction is set to the inner diameter R2 of the drive side tubular portion 82a (more specifically, the drive side hole portion 87 inner diameter) or less. As in the present embodiment, when the heights of the driven protrusions 95a are the same, the maximum outer diameter R1 of the second insertion portion 90b is the diameter of the circumscribed circle in contact with the driven protrusions. On the other hand, when the heights of the driven projections 95a are different from each other, the maximum outer diameter R1 in the rotation direction of the second insertion portion 90b is as follows. That is, of each driven-side protrusion, twice the length from one end of the highest driven-side protrusion in the rotation direction to the center of the driven-side spherical portion 95a is the maximum outer diameter in the rotation direction of the second insertion portion 90b. Become. Thus, by making the maximum outer diameter R1 of the second insertion portion 90b equal to or less than the inner diameter R2 of the drive side cylindrical portion 82a, as shown in FIG. 10A, the following of the drive side protrusions 94a and 94b The length L1 from the side end (coupling member side end) to the driving side end (photoreceptor gear side end) of the driven projection 95a is communicated from the driven side end of the driving side cylindrical portion 82a It can be made shorter than the length L2 to the portion 84.

Next, the attachment of the connecting member 90 to the photosensitive gear 82 will be described.
First, as shown in FIG. 8, the coil spring 73 is inserted into the drive side hole 87 of the drive side cylindrical portion 82a. Next, the first drive projection 94a is inserted into the first guide groove 86a, and the second drive projection 94b is inserted into the second guide groove 86b. Adjust the rotational position.

  In the present embodiment, the height h2 of the first drive side projection 94a is made longer than the height h1 of the second drive side projection 94b that is the phase alignment projection, and the second guide groove 86b that is the phase alignment groove 86b. The groove depth is made shallower than the groove depth of the first guide groove 86a, and the groove depth is made shorter than the height h2 of the first drive-side projection 94a. Accordingly, the first drive side protrusion 94a cannot be inserted into the second guide groove 86b, and only the second drive side protrusion 94b can be inserted into the second guide groove 86b. As a result, the connecting member 90 can be attached to the photosensitive gear 82 at a prescribed phase with respect to the photosensitive gear 82. In other words, in the present embodiment, the second driving side protrusion 94b and the second guide groove 86b constitute a first phase matching portion.

  Further, the diameter of the second drive side projection 94b, which is the phase matching projection, is made larger than the diameter of the first drive side projection 94a, and the groove width of the first guide groove 86a is the groove width of the second guide groove 86b. It may be made narrower than the diameter of the second drive-side protrusion 94 b. Also with this configuration, the second drive-side protrusion 94b can be inserted only into the second guide groove 86b, and the connecting member 90 can be attached to the photoreceptor gear at a prescribed phase with respect to the photoreceptor gear.

  Further, the diameter of the second drive-side projection 94b, which is the phase matching projection, is smaller than the diameter of the first drive-side projection, and the groove width of the second guide groove 86b is greater than the groove width of the first guide groove 86a. It may be made narrower than the diameter of the first drive-side protrusion 94a. Also with this configuration, the second drive-side protrusion 94 b can be inserted only into the second guide groove 86 b, and the connecting member 90 is attached to the photosensitive gear 82 at a prescribed phase with respect to the photosensitive gear 82. it can.

  Further, a recess is provided at a location that does not interfere with the drive transmission of the second drive-side protrusion 94b, and a protrusion that fits into the recess is provided in the second guide groove 86b, so that the protrusion of the second guide groove 86b The first drive protrusion 94a can not be inserted into the second guide groove 86b. As a result, the second drive side protrusion 94 b can be inserted only into the second guide groove 86 b, and the connecting member 90 can be attached to the photoconductor gear 82 with a prescribed phase with respect to the photoconductor gear 82. Alternatively, a protrusion may be provided at a location that does not interfere with the drive transmission of the second drive-side protrusion 94b, and a recess in which the protrusion is fitted may be provided in the second guide groove 86b.

  Next, the driving side spherical portion 91 of the first insertion portion 90a is inserted into the driving side hole portion 87, the first driving side projection portion 94a is inserted into the first guide groove portion 86a, and the second driving side projection portion 94b is inserted into the first driving groove portion 94b. Insert into the two guide grooves 86b. Then, the spring receiver 96 of the connecting member 90 is fitted into the coil spring 73, and one end of the coil spring 73 is attached to the connecting member 90. Then, the connecting member 90 is driven against the biasing force of the coil spring 73 until the first and second drive-side protrusions 94a and 94b are positioned in the communication portion 84 that connects the guide groove and the drive-side groove 85. Push into the side cylindrical portion 82a.

  As described above, in the present embodiment, the maximum outer diameter R1 of the second insertion portion 90b is equal to or less than the inner diameter R2 of the drive side cylindrical portion 82a (more specifically, the inner diameter of the drive side hole 87). Thereby, the second insertion portion 90 b can be inserted into the drive side hole 87. As a result, in order to miniaturize the image forming apparatus, the drive side end (photoreceptor gear side end) of the driven side projection 95a from the driven side end (coupling member side end) of the drive side projection 94a, 94b Portion L) can be shorter than the length L2 from the driven side end of the drive side cylindrical portion 82a to the communication portion 84.

  That is, when the L1 is shorter than the L2, in order to position the drive side protrusion 94b in the communication portion 84, the drive side cylindrical portion 82a is extended to the portion of the driven side protrusion 95a of the second insertion portion 90b. Need to insert. In the present embodiment, the maximum outer diameter R1 of the second insertion portion 90b is equal to or less than the inner diameter R2 of the drive side cylindrical portion 82a (more specifically, the inner diameter of the drive side hole 87). Therefore, when the connecting member 90 is inserted into the drive side cylindrical portion 82a until the drive side projection 94b is positioned in the communication portion 84, as shown in FIG. 11, the driven side spherical portion 92 of the second insertion portion 90b and The driven projection 95 a is inserted into the driving hole 87.

  Next, when the connecting member 90 is pushed into the communicating portion 84 which connects the guide groove portion and the driving side groove portion 85, the connecting member 90 is rotated and the driving side protrusions 94a and 94b pass through the communicating portion 84. And move to the drive side groove 85.

  Even if the second insertion portion 90b has the same shape (congruent) as the first insertion portion 90a, the driven-side spherical portion 92 of the second insertion portion 90b enters the drive-side hole portion 87 of the drive-side cylindrical portion 82a. When the driven side projection 95a enters the guide groove, the connecting member 90 can be inserted into the drive side cylindrical portion 82a until the drive side projection 94b is positioned at the communication portion 84. However, if the connecting member is rotated in order to move the driving side protrusion 94 from the guide groove to the driving side groove 85, the driven side protrusion hits the wall that partitions the guide groove and the driving groove, and is connected. The member can not be rotated. As a result, the drive-side protrusion 94 can not be moved from the guide groove to the drive-side groove 85 through the communication portion.

  On the other hand, in the present embodiment, as shown in FIG. 10 (b), the maximum outer diameter R1 of the second insertion portion 90b is set to the inner diameter R2 (more specifically, the driving side hole of the driving side cylindrical portion 82a). The driven side spherical portion 92 and the driven side protruding portion 95a of the second insertion portion 90b are inserted into the driving side hole portion 87. Accordingly, the connecting member 90 can be rotated in the direction indicated by the arrow α in FIG. 11 in a state where the second insertion portion 90b is inserted into the drive side cylindrical portion. As a result, the connecting member 90 can be rotated to move the driving side protrusions 94 a and 94 b to the driving side groove 85 through the communication part 84.

  As described above, in the connecting member 90 of the present embodiment, the driving side end portions (coupling member side end portions) of the driving side protrusion portions 94a and 94b to the driving side end portion (photoconductor gear side) of the driven side protrusion portions 95a. Even if the length L1 to the end portion is shorter than the length L2 from the driven end of the drive side cylindrical portion 82a to the communication portion 84, the drive side protrusions 94a and 94b are moved to the drive side groove It can be done.

  Moreover, in this embodiment, since the shape of the 1st insertion part 90a and the 2nd insertion part 90b is clearly different, the 1st insertion part 90a and the 2nd insertion part 90b are not mistaken. Even if the second insertion portion 90b is inserted into the driving side cylindrical portion 82a and the connecting member 90 is attached to the photosensitive gear 82 by mistake, the driven side projection may be inserted into the driving side groove portion. Otherwise, the connecting member 90 can not be attached to the photosensitive gear 82. Thereby, the erroneous attachment of the connection member 90 can be prevented.

  Next, when the drive side protrusions 94a and 94b contact the side surface of the drive side groove 85 and the rotation of the connecting member 90 is restricted, the hand is released from the connecting member 90. Then, the connecting member 90 is moved to the coupling member side by the biasing force of the coil spring 73, and the drive side protrusions 94 a and 95 b are inserted into the drive side groove 85. Thus, the connecting member 90 is attached to the photosensitive gear 82. Then, the photoreceptor gear 82 to which the connecting member 90 is attached is attached to the back side plate 1b via the bearing 100 (see FIG. 3).

  In the present embodiment, as described above, the height of the first drive side protrusion 94a and the height of the second drive side protrusion 94b are made different, the groove depth of the second guide groove 86b is made shallow, and the second Only the second drive side protrusion 94 b can be inserted into the guide groove 86 b. Thus, the connecting member 90 is attached to the photosensitive gear at a prescribed phase with respect to the photosensitive gear. As a result, as shown in FIG. 12, the third driven side large circle portion 92c of the driven side spherical portion is positioned at a position where the angle γ by the second guide groove 86b is always rotated clockwise in the drawing. A connecting member 90 is attached to the photoreceptor gear 82.

  When the drive side protrusions 94a and 94b are inserted into the drive side groove 85, the drive side protrusions 94 face the retaining portions 85a, and the connecting member 90 gets out of the photosensitive gear 82 as described above. Is prevented. In the configuration described in Patent Document 1, the connecting member 90 is assembled to the photoconductor gear 82, and then the stopper member is fixed to the photoconductor gear by snap-fit so that the photoconductor gear of the connecting member 90 is pulled out. It is preventing. As described above, the configuration described in Patent Document 1 requires a separate retaining member, which leads to an increase in the cost of the apparatus due to an increase in the number of parts. Further, the increase in the number of assembling steps leads to an increase in manufacturing cost.

  On the other hand, in the present embodiment, since the retaining portion 85a is provided on the photoconductor gear, the number of parts can be reduced and the cost of the apparatus can be reduced. In addition, the number of assembling steps can be reduced, and the manufacturing cost can be reduced.

FIG. 13 is a perspective view of the bearing 100. FIG.
As shown in FIG. 13, the bearing 100 has a cylindrical receiving portion whose outer peripheral surface is fitted into a hole in the back side plate 1b and whose inner peripheral surface rotatably receives the driving side cylindrical portion of the photoconductor gear. 101 and a restricting protrusion 102.

  As shown in FIG. 3 above, the drive side cylinder of the photosensitive gear 82 is inserted so that the restriction projection 102 of the bearing 100 fitted and fixed in the hole of the back side plate 1b is inserted into the insertion hole 83. The portion 82 a is inserted into the receiving portion 101 of the bearing 100. Thus, the photosensitive gear 82 is rotatably supported by the back side plate 1 b via the bearing 100.

FIG. 14 is a view for explaining the regulation by the regulation projection portion 102 of the bearing 100.
As shown in FIG. 14, when the connecting member 90 is pushed into the driving side cylindrical portion 82 a of the photoconductor gear 82, the spring of the connecting member 90 is moved before the driving side protrusions 94 a and 94 b reach the communicating portion 84. The catch 96 abuts on the control protrusion 102. Thus, axial movement of the connecting member 90 is restricted before the drive side projections 94 a and 94 b in the drive side groove 85 move to the communication part 84. As a result, even if the connecting member 90 is rotated relative to the photosensitive gear 82, the drive side protrusions 94a and 94b in the drive side groove 85 move to the guide groove through the communication part 84. Absent. As a result, after the photosensitive gear 82 is supported by the back side plate via the bearing 100, the connecting member 90 does not come out of the photosensitive gear 82.

FIG. 15 is a perspective view of the coupling member 41, and FIG. 16 is a cross-sectional perspective view of the coupling member 41.
The coupling member 41 includes a shaft insertion portion 41a and a driven side cylindrical portion 41b. The coupling member 41 is preferably made of polyacetal resin (POM) which is excellent in mechanical strength, abrasion resistance, and slidability.

  The driven side tubular portion 41b of the coupling member 41 has an opening shape only on the drive side, and has a driven side hole portion 143 into which the driven side spherical portion 92 of the connecting member 90 is inserted. Further, the driven side tubular portion 41b is provided with two driven side groove portions 142 into which the driven side protrusion portions 95a of the connecting member 90 are inserted with an interval of 180 ° in the rotation direction. The groove depth d1 of the driven groove 142 is slightly longer than the height h1 of the driven projection 95a. Further, on the bottom surface of the driven side spherical portion 92, a phasing convex portion 144 is formed at a position shifted with respect to the rotation center.

  As shown in FIG. 16, the phase matching convex portion 144 has a mountain shape that gradually decreases in height from the center toward the outside. Further, as shown in FIG. 15, the phase matching convex portion 144 is formed to a position that is retreated by a length emm from the position of the driven side groove portion 142.

FIG. 17 is a cross-sectional perspective view showing a state in which the driven-side spherical portion 92 of the connecting member 90 is inserted into the driven-side cylindrical portion 41 b of the coupling member 41.
When the coupling member 41 and the connecting member 90 are to be connected in a state where the phase alignment convex portion 144 is positioned on the lower side in the figure, the third driven side great circle portion 92c of the driven side spherical portion 92 is phase-adjusted. It hits part 144. As a result, the driven-side spherical portion 92 can not be inserted into the driven-side cylindrical portion 41b of the coupling member 41, and the driven-side projection 95a is not inserted into the driven-side groove portion 142. That is, when the phase matching convex portion 144 is in phase with the portion of the driven side spherical portion 92 cut by the third driven side large circular portion 92 c, the driven side spherical portion 92 has the following cylindrical shape. The driven side projection 95a is inserted into the driven side groove 142, and the drive connection is performed. That is, in the present embodiment, the second phasing portion is configured by the phasing convex portion 144 and the notch portion where the third driven large circle portion 92c of the driven spherical portion 92 is cut.

  As described above, in the present embodiment, the photoconductor gear 82 and the connecting member 90 are attached with a specified phase, and the connecting member 90 and the coupling member 41 are driven and connected with a specified phase. And the coupling member 41 can be drivably connected at a prescribed phase.

  As described above, the photosensitive gear 82 is a resin molded product, and due to sinks and the like, the photosensitive gear 82 is not perfectly circular but slightly elliptical. As a result, the photosensitive gear has a speed fluctuation of one rotation cycle. If the phase of the speed fluctuation of the photoconductor gear is different for each color, a color shift corresponding to the phase occurs, and the color image is affected. More specifically, if there is a speed fluctuation in the photoconductor gear, the speed of the photoconductor drum 40 also fluctuates according to the speed fluctuation, and the image expands and contracts according to the speed fluctuation. That is, when the speed of the photosensitive drum 40 is high, an image on which writing or transfer has been performed expands, and when the speed of the photosensitive drum 40 is low, an image on which writing or transfer has been performed contracts. Color misregistration can be suppressed by matching the phase of speed fluctuations of the photoconductor gears of the respective colors so that the extended portions and the contracted portions of the images of the respective colors are superimposed. The phasing of the photoreceptor gears of the respective colors is performed, for example, by marking the location where the maximum diameter of the photoreceptor gear is to be made and attaching the photoreceptor gears of the respective colors to the back side plate with the indicia as marks.

Also in the photosensitive drum 40 to which the coupling member is attached, the speed fluctuation of one rotation cycle occurs due to the eccentricity of the photosensitive drum 40 or the like. For this reason, it is necessary to assemble the photosensitive drum 40 to the apparatus main body by matching the phase of the speed fluctuation of the photosensitive drum 40 of each color.
In the present embodiment, the driven-side protrusions 95a are provided with an interval of 180 ° in the rotation direction. Therefore, even if the coupling member is rotated 180 ° from the phase in which the driven protrusion 95a and the driven groove 142 are in phase, the rotation direction of the driven protrusion 95a and the driven groove 142 Are in phase. As a result, the photosensitive drum 40 may be assembled to the apparatus main body in a state where the phase is 180 degrees out of phase with the prescribed phase, and there is a possibility that color misregistration may occur.

  On the other hand, in the present embodiment, since the phase matching convex portion 144 is provided, the third driven large circle portion is obtained even if the phases in the rotational direction of the driven protrusion portion 95a and the driven groove portion 142 match. When 92 c is opposed to the phase matching convex portion 144, it is not driven and connected. From this state, the coupling member 41 is rotated relative to the coupling member 90 by 180 °, and the driven spherical portion is first inserted into the driven cylindrical portion to perform drive coupling. As a result, the photosensitive drum 40 can be assembled to the apparatus main body with a prescribed phase, and color shift can be suppressed.

  Further, the drive side protrusions 94a and 94b are also provided at an interval of 180 ° in the rotational direction. Therefore, when the heights of the drive side protrusions and the groove depths of the guide grooves are made equal, the connecting member is rotated 180 ° from the state where the rotational direction of the drive side protrusions and the guide grooves are in phase. Even if it rotates with respect to a gear, the phase of the rotation direction of the driven-side protrusion 95a and the driven-side groove 142 matches. Therefore, even if the coupling member is connected to the connecting member at a prescribed phase and the speed fluctuation phase of each photosensitive drum 40 is matched, the phase of the photosensitive gear speed fluctuation deviates by 180 ° with respect to the prescribed phase. There is a risk of However, in the present embodiment, the heights of the drive side protrusions are made different so that the first drive side protrusions can not be inserted into the second guide groove. As a result, it is possible to prevent the rotational speed phase of the photosensitive gear from being 180 ° out of phase with respect to the speed fluctuation of the other photosensitive gears, and to suppress the color shift.

  When the unit including the photosensitive drum is mounted on the apparatus, if the coupling member 41 attached to the drum shaft 40a and the connecting member 90 are out of phase, the edge of the driven cylindrical portion of the coupling member The driven-side protrusion 95a hits the part, or the third driven-side great circle part 92c hits the phase matching convex part 144. In this state, when the unit including the photosensitive drum is further pushed into the apparatus main body, the connecting member 90 moves to the back side while compressing the coil spring 73. As a result, even if the driving connection between the coupling member 41 and the connecting member 90 is not performed, the unit including the photosensitive drum can be mounted on the apparatus main body.

  When the connecting member 90 is rotationally driven together with the photoconductor gear 82, the phase of the driven-side projection 95a and the driven-side groove 142 is matched, and the contact between the third driven-side great circle 92c and the phase-adjusting convex 144 is released. And the coupling member 90 and the coupling member 41 are in phase with each other. Then, the connecting member 90 moves to the coupling member side by the urging force of the coil spring 73, the driven side spherical portion 92 enters the driven side hole portion 143, and the driven side projection portion 95 a enters the driven side groove portion 142. As a result, the connecting member 90 and the coupling member 41 are drivingly connected with a specified phase, and the driving force is transmitted from the connecting member 90 to the coupling member 41.

  When there is a deviation (hereinafter referred to as an axial misalignment) between the rotation center of the photoconductor gear and the rotation center of the drum shaft 40a, the connecting member 90 can be driven and connected as shown in FIG. . In this embodiment, the first insertion portion inserted into the drive side cylindrical portion 82a of the photosensitive member gear 82 of the connection member and the second insertion portion inserted into the driven side cylindrical portion of the coupling member are spherical. . Thereby, when there is a misalignment, the connecting member can be inclined smoothly, and the misalignment can be absorbed well. Specifically, the arc-shaped surfaces of the first, second and third drive side large circular portions 91a, 91b and 91c of the drive side spherical portion inserted into the drive side cylindrical portion 82a of the photosensitive gear 82 drive The inner peripheral surface of the side hole 87 is smoothly slid, and the connecting member 90 is inclined smoothly with respect to the photoconductor gear 82. Further, the arc-shaped surfaces of the first, second and third driven side large circular portions 92a, 92b and 92c of the driven side spherical portion inserted into the driven side cylindrical portion of the coupling member are the driven side hole portion 143. The connecting member 90 is smoothly inclined with respect to the coupling member. Thereby, the connection member 90 can be smoothly inclined, and axial displacement can be suppressed.

FIG. 18 is a cross-sectional view in which the coupling member 41 and the connecting member 90 are cut in a direction perpendicular to the protruding direction of the driven-side protruding portion 95a.
As shown in FIG. 18A, the height of the phasing convex portion 144 is such that when the connecting member 90 is not inclined, there is a predetermined gap with respect to the side surface of the first driven side large circle portion 92a. It is height. As shown in FIG. 18B, even if this gap is inclined at the maximum inclination angle + θ1 in the direction orthogonal to the projecting direction of the driven projection 95a of the connecting member 90, the first driven large circle 92a is in phase. It is a gap not in contact with the fitting convex portion 144.

  Further, as shown in FIG. 15, the phase alignment convex portion 144 is not formed up to a location that is flush with the side surface of the driven side groove portion 142, and is retreated by emm with respect to the side surface of the driven side groove portion 142. Therefore, as shown in FIG. 18A, when the connecting member 90 is not inclined, a predetermined gap is formed between the side surface of the phase matching convex portion 144 and the side surface of the second driven side large circle portion 92b. . As shown in FIG. 18C, even if this gap is inclined at the maximum inclination angle -θ1 in the direction orthogonal to the projecting direction of the driven projection 95a of the connecting member 90, the second driven large circle 92b is The gap is not in contact with the side surface of the phase matching projection.

FIG. 19 is a cross-sectional view in which the coupling member 41 and the connecting member 90 are cut in parallel to the protruding direction of the driven-side protruding portion 95a.
As shown in FIG. 19A, the phasing convex portion 144 has a mountain-like shape in which the cross-section decreases in height from the center toward the end. Then, as shown in FIG. 19 (b) and FIG. 19 (c), the inclination angle θ3 of the inclined surface of the phasing convex portion 144 is a direction in which the connecting member 90 is parallel to the projecting direction of the driven projection 95a. Is set such that the side surface of the first driven side large circle portion 92a does not abut on the phase matching convex portion 144 when it is inclined at the maximum inclination angle .theta.2.

  Thus, in this embodiment, since the phase alignment convex part 144 does not inhibit the inclination of the connecting member 90, the connecting member 90 can absorb the axial misalignment satisfactorily. The maximum inclination angle of the connecting member 90 is determined such that the connecting portion 93 of the connecting member 90 abuts against the edge of the driven cylindrical portion of the coupling member 41 or the edge of the driving cylindrical portion of the photosensitive gear. It is the angle at which the inclination is restricted by hitting.

  Further, the configuration for matching the phase of the driven side (the coupling member 41 and the connecting member 90) may be the same as the configuration for matching the phase of the driving side (the photosensitive gear and the connecting member). That is, the lengths of the driven side protrusions 94b are made different from each other, and the groove depths of the driven side groove parts 142 are made different from each other so that the driven side protrusions 94b cannot be inserted into other than the determined driven side groove parts 142. It is a configuration.

  Further, in the present embodiment, the drive side protrusions 94a and 94b to which the driving force is transmitted from the photosensitive member gear of the connecting member 90 and the driven side projections 95a to transmit the driving force to the coupling member are cylindrical. There is. Thereby, the advantage that an angular velocity fluctuation | variation can be suppressed compared with the conventional structure which made the drive side protrusion part and the driven side protrusion part hemispherical can be acquired. Below, it demonstrates concretely using drawing.

  FIG. 20 is a view for explaining the drive transmission between the conventional connection member and the coupling member, and (a) is a schematic view seen in a direction orthogonal to the inclination direction of the connection member, (b) Fig. 20 (a) is a schematic view seen from the top, and Fig. 20 (c) is a schematic view seen in the axial direction. FIG. 21 is a view showing a state rotated 90 ° from the state of FIG. 20, where (a) is a schematic view seen in a direction orthogonal to the inclination direction of the connecting member, (b) Fig. 21 (a) is a schematic view from above, and (c) is a schematic view from the axial direction.

  When the driven-side projection 195 is hemispherical, as shown in FIG. 20C, the downstream end of the driven-side projection 195 in the rotational direction, which is a groove-contacting portion that is in contact with the side surface of the driven groove 142 As it goes, it becomes an arc shape that is located on the upstream side in the rotational direction. As shown in FIG. 20, when the protrusion direction of the driven protrusion 195 is in the direction orthogonal to the off-axis direction, substantially the entire of the driven protrusion 195 is in the driven groove. Therefore, at this time, as shown in FIG. 20C, the driven-side spherical portion side of the driven-side projection portion 195 is in contact with the side surface of the driven-side groove portion 142.

  When this state is rotated in the direction of arrow F in FIG. 20 (c), the driven projection 195 on the left side in FIG. 20 (c) axially moves in the driven groove in the direction of separating from the photosensitive gear. The right driven projection 195 of 20 (c) moves in the axial direction in the driven groove in a direction approaching the photosensitive member gear. At this time, the amount of the driven-side protrusion 195 entering the driven groove decreases, and the contact position of the driven-side protrusion 195 with the side surface of the driven groove changes toward the top. When the driven side protrusion 195 is hemispherical, as described above, the downstream end in the rotational direction of the driven side protrusion 195 that contacts the driven side groove 142 is positioned upstream in the rotational direction toward the top. For this reason, as shown in FIG. 21 (c), even if the connecting member 190 rotates 90 °, the coupling member 41 does not rotate 90 ° and is positioned at a position that is receded by δθ in the rotation direction. The angular velocity of the member 41 is slower than the angular velocity of the connecting member 90.

Then, when it is further rotated in the direction of arrow F in FIG. 21 (c) from the state of FIG. 21, the driven-side projection 195 positioned on the upper side in FIG. 21 (a) Move in the axial direction. Further, in FIG. 21A, the driven-side projection 195 positioned on the lower side axially moves in the driven groove so as to move away from the photosensitive gear. At this time, the contact position of the driven-side protrusion 195 with the side surface of the driven groove changes from the top to the driven-side spherical part, and rotates 90 ° from the state of FIG. The state is the same as that of FIG. 20 except that the positions of the protrusion 195 and the driven groove are switched. At this time, the delay of the coupling member 41 is eliminated and, like the connecting member 90, it is rotated by 180 °. That is, while rotating by 90 ° from the state of FIG. 21, the coupling member is rotated by Δθ many times, and the angular velocity is accelerated with respect to the connecting member 90. As described above, when the driven-side protrusion is hemispherical, angular velocity fluctuations with a half rotation period occur.
In the above description, the speed fluctuation between the connecting member and the coupling member has been described. However, when the drive side protrusion is hemispherical, the connecting member is 1⁄2 between the photosensitive gear and the connecting member. Speed fluctuation occurs in the cycle.

  FIG. 22 is a diagram for explaining the drive transmission between the coupling member 90 and the coupling member 41 in the present embodiment, and (a) is a schematic view seen in the direction orthogonal to the inclination direction of the coupling member 90. (B) is the schematic seen from the top of Drawing 22 (a), (c) is the schematic seen from the direction of an axis. Moreover, FIG. 23 is a figure which shows the state rotated 90 degrees from the state of FIG. 22, (a) is the schematic seen from the direction orthogonal to the inclination direction of a connection member, (b) Fig. 23 (a) is a schematic view from above, and (c) is a schematic view from the axial direction.

  In the present embodiment, the driven-side projection 95a has a cylindrical shape. As a result, as shown in FIG. 22C, the downstream end in the rotational direction, which is the groove contact portion contacting the side surface of the driven groove of the driven projection 95a, has a linear shape extending straight in the radial direction. The locations of the side protrusions 95a that are in contact with the driven groove 42 are the same in the rotational direction from the driven spherical portion 92 to the top. When it is rotated in the direction of arrow F in FIG. 22 (c) from the state shown in FIG. 22, the entry of the follower groove of the follower-side projection 95a is reduced, and as shown in FIG. Only the top side of the side projection 95 a is in the state of being inserted into the driven groove 142. As a result, only the downstream end portion in the rotation direction of the top portion of the driven-side projection portion comes into contact with the side surface of the driven-side groove portion. However, since the downstream end of the driven projection in the rotational direction has a straight shape extending straight in the radial direction, only the downstream end of the top of the driven projection in the rotational direction abuts on the side surface of the driven groove. However, the coupling member 41 rotates at the same angle as the connecting member 90 without delaying the rotation of the connecting member 90. As a result, the coupling member 41 can be rotated at an equal speed even if there is axial misalignment.

  Similarly, since the drive side protrusions 94a and 94b also have a cylindrical shape, the connecting member 90 can be rotated at the same speed without the speed of the connecting member 90 fluctuating in the drive transmission from the photosensitive gear to the connecting member. .

  Further, in the present embodiment, by making the drive side protrusions 94a and 94b and the driven side protrusions 95a into a cylindrical shape, the downstream end portion in the rotational direction, which is the groove abutting portion abutting on the side surface of the groove, The arc surface protrudes to As a result, the contact between the protruding portion and the side surface of the groove portion is a point contact when viewed from the radial direction, and as shown in FIG. 22A, the connecting member smoothly in the direction orthogonal to the protruding direction of the protruding portion. 90 can be tilted. The above-mentioned point contact is an ideal state in design, and includes a state in which the contact width is somewhat in practice.

  FIG. 24 shows a photoconductor when a conventional connecting member having a driving-side protrusion and a driven-side protrusion is hemispherical and the shaft center of the drum shaft is shifted by a predetermined amount with respect to the rotation shaft of the photoconductor gear. It is the graph which investigated the speed fluctuation of the drum. As shown in FIG. 24, it can be seen that the photosensitive drum has a speed fluctuation at a predetermined cycle.

FIG. 25 shows the case where the drive side projection and the driven side projection are connected by shifting the axial center of the drum shaft by a predetermined amount with respect to the rotation axis of the photosensitive gear using the connecting member of the present embodiment having a cylindrical shape. It is the graph which investigated the speed fluctuation of the photoconductive drum.
As shown in FIG. 25, it can be seen that the speed fluctuation of the photosensitive drum can be sufficiently suppressed as compared with the case of the conventional configuration shown in FIG.

In addition, if the drive-side protrusions 94a and 94b and the driven-side protrusions 95a have a shape in which at least the groove contact portion contacting with the side surface of the groove (142, 85) is straight in the radial direction and protrudes in the rotational direction Good. Therefore, for example, a column shape having a rounded rectangular shape as shown in FIG. 26 or a column shape having an elliptical cross section may be used.
Further, when the groove contact portion in contact with the side surface of the groove (42, 85) of the projection (95a, 94a, 94b) is an arc surface, the central angle θy of the arc is the projection direction of the projection of the connecting member 90 More than twice the maximum inclination angle θ1 in the orthogonal direction. Thus, even when the connecting member 90 is inclined at the maximum inclination angle θ1, the arc surface of the projection (95a, 94a, 94b) can be made to abut on the side surface of the groove (142, 85). Thereby, even when the connecting member 90 is inclined at the maximum inclination angle θ1, the contact between the groove and the protruding portion when viewed from the protruding direction of the protruding portion can be made point contact, and the connecting member 90 can be inclined smoothly. Can do.

  Further, although the drive transmission unit for transmitting the driving force to the photosensitive member has been described above, the present invention is not limited to this, and the drive transmission to the developing roller, the drive transmission to the fixing roller, the drive transmission to the intermediate transfer belt, etc. The drive transmission of this embodiment can be used.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect 1)
On the inner peripheral surface of the first rotating body such as a photosensitive member gear 82 having a hole at the rotation center, the second rotating body such as the coupling member 41 having a hole at the rotation center, and the hole of the first rotating body The first groove such as an axially extending drive groove 85 provided in the axial direction, the second groove such as an axially extending driven groove 142 provided on the inner circumferential surface of the hole of the second rotary member, and the first groove It has first projections such as drive side projections 94a and 94b projecting in the radial direction to be engaged with the one groove, and is engaged with the first insertion part 90a and the second groove that are inserted into the holes of the first rotating body. A second insertion portion 90b having a projection portion such as a driven projection portion 95a projecting in the radial direction to be mated and inserted into the hole of the second rotating body; and the first insertion portion 90a and the second insertion portion 90b Drive transmission device having a connecting portion 93 for connecting the first rotating body and the second rotating body. The first insertion portion 90a is axially movable in the hole portion of the first rotating body, and the first projection portion is at a position different from the formation position of the first groove portion in the rotational direction. The first protrusion inserted into the hole at a position different from the formation position of the first groove in the rotational direction, which can be inserted into the hole of the single rotation body, is located in the first groove inside the hole. And after the first groove portion is located in the first groove portion, the hole portion and the first groove portion of the first rotary body are configured so that the first protrusion portion can move in the first groove portion toward the second rotary body side. The maximum outer diameter of the insertion portion 90b was made smaller than the inner diameter of the hole portion of the first rotating body.
As described above, in the drive transmission device under development, the connecting member 90 cannot be sufficiently shortened. This is because the communication portion 84 in which the guide grooves 86a and 86b communicate with the first groove portion such as the drive side groove portion 85, the second groove portion such as the driven side groove portion 142 and the second projection such as the driven side projection 95a. The first protrusions such as the drive-side protrusions 94a and 94b move in the first groove when the connecting member 90 is pushed in by the second rotating body such as the coupling member 41 because the phases in the rotation direction are not matched. It is necessary to provide it on the inner side of the hole than the moving range. When the communication part 84 is within the movement range, there is the following problem. That is, the phase of the rotation direction of the second groove portion and the second protrusion portion is not matched, and the connecting member 90 is pushed in by the second rotating body, the first protrusion portion moves in the first groove portion, and the communication portion 84. When the connection member 90 rotates to some time when approaching, the first projection part moves from the first groove part to the guide grooves 86a and 86b through the communication part 84. Then, the connecting member 90 can not be pushed any more and the second rotating body can not be brought into the defined position in the apparatus. Further, once the second rotating body is separated from the connecting member 90 in order to reassemble the second rotating body, the connecting member 90 moves to the second rotating body side by the biasing force of the coil spring 73. At this time, the first projection moves in the guide groove and the first projection slips out of the hole, and the connecting member 90 is detached from the hole of the first rotary body. In order to prevent this problem, it is necessary to provide the communicating portion 84 on the inner side of the hole than the above-mentioned moving range. Therefore, the connecting member is set so that the length from the first protruding portion to the second protruding portion is longer than the length from the second rotating body side end portion of the first rotating body hole portion to the communication portion between the first groove portion and the guide groove. 90 must be configured. This is because if the length from the first projection to the second projection is shorter than the length from the second rotary member side end of the first rotary body hole to the communicating portion 84, the first projection can be made into the first groove It is because it can not be located in Specifically, if the position of the second protrusion in the rotational direction and the position of the first protrusion in the rotational direction are different from each other, the second insertion portion may be inserted before the first protrusion reaches the communication portion 84. The second projection abuts against the second rotary body side end face of the hole of the first rotary body, and the first projection can not be positioned in the guide grooves 86a and 86b. In addition, when the position of the first protrusion in the rotation direction is the same as the position of the second protrusion in the rotation direction, the second protrusion enters the guide grooves 86a and 86b, and the first protrusion reaches the communication portion 84. it can. However, the second protrusion abuts on the side surfaces of the guide grooves 86a and 86b, so that the connecting member 90 can not be rotated, and the first protrusion can not be positioned in the guide groove through the communication portion 84.
As described above, in the drive transmission device under development, at least the length from the first protrusion to the second protrusion is the first groove and the guide groove from the second rotary member side end of the first rotary member hole. It is necessary to form the connecting member 90 so as to be longer than the length up to the point of communication with 86a and 86b, and the connecting member 90 can not be made sufficiently short.
On the other hand, in (Aspect 1), since the maximum outer diameter of the second insertion portion is smaller than the inner diameter of the hole portion of the first rotating body, the second insertion portion is inserted into the hole portion of the first rotating body can do. Thereby, even if it is a connection member shorter than the length from the end part of the hole part of the 1st rotary body to the location where the projection part of the 1st insertion part is located in the 1st groove part from the 2nd rotary body side end, Can be assembled to a single rotating body. Specifically, the first insertion portion is inserted into the hole of the first rotary body to a point where the first projection is positioned in the first groove by the second insertion portion entering the hole of the first rotary body. can do. Moreover, a connection member can be rotated in the state which the 2nd insertion part was inserted in the hole of a 1st rotary body. As a result, the first projection can be positioned in the first groove, and the coupling member can be assembled to the first rotating body.
Further, in (aspect 1), the first insertion portion is configured to be movable in the axial direction in the hole portion of the first rotating body. Thereby, when the phase of the rotation direction of a 2nd groove part and a 2nd projection part does not match, and a 2nd insertion part is not inserted in the hole of a 2nd rotary body, a 1st insertion part is a 1st rotary body. The second rotary body can be positioned at a predetermined position in the apparatus even if it moves in the hole and the second insertion portion is not inserted into the hole of the second rotary body.
In addition, the first protrusion can be inserted into the hole of the first rotary member at a position different from the formation position of the first groove in the rotational direction, and is different from the formation position of the first groove in the rotational direction Since the first protrusion inserted into the hole at the position can be positioned in the first groove inside the hole, the first groove extends to the second rotating body side end of the hole of the first rotating body. Even if the configuration does not extend and stops halfway, the first protrusion can be positioned in the first groove.
Further, after being positioned in the first groove portion, the first projection portion is moved and assembled in the first groove portion toward the second rotating body, so that the phase in the rotation direction between the second groove portion and the second projection portion is When the connecting member is pushed in by the second rotating body and the first insertion portion moves into the hole portion, the first projecting portion is different from the formation position of the first groove portion in the rotational direction. It can suppress that the 1st projection part inserted in the hole part reaches to a place located in a 1st groove part inside a hole part. Thereby, it can suppress that a 1st projection part remove | deviates from a 1st groove part.

(Aspect 2)
In (Aspect 1), the first groove such as the drive groove 85 has a retaining portion 85a for stopping the first protrusions such as the drive protrusions 94a and 94b from coming off the first groove, and The hole of the first rotary member of the gear 82 has an opening at a position different from the position where the first groove is formed in the rotational direction, and extends in the axial direction to insert the first insertion portion 90a into the hole In addition, the guide groove portions 86a and 86b for guiding the first protrusion portion to the inside of the hole portion, and the communication portion 84 for communicating the guide groove portion and the first groove portion, the connecting member 90 is a coupling member or the like. When moving to the second rotary body side, the first protrusions such as the drive side protrusions 94a and 94b abut against the retaining portions 85a, and the first insertion portion 90a of the connecting member 90 performs the first rotation of the photosensitive gear 82 or the like. It is possible to prevent the body from coming off.
In addition, the first protrusions such as the drive side protrusions 94a and 94b are inserted into the guide grooves 86a and 86b, and the guide grooves 86a and 86b are positioned in the communication portion 84 between the first grooves such as the drive groove 85 and the like. The first protrusions are inserted into the guide grooves 86a and 86b. Then, by rotating the connecting member 90, the first projection in the guide groove 86a, 86b can be moved to the first groove through the communication part 84, and the first projection can be moved in the hole. It can be located in one groove part. Even if the retaining portion is formed by integral molding of a rotating body such as a photoconductor gear, the first protrusion can be positioned in the first groove and the first insertion portion can be inserted into the hole. . Accordingly, the number of parts is reduced as compared with the configuration described in Patent Document 1 in which a retaining member that is a separate member from the rotating body is provided, the connecting member is attached to the rotating body, and then the retaining member is assembled to the rotating body. be able to. As a result, the cost of the apparatus can be reduced and the number of assembling steps can be reduced.

(Aspect 3)
In (Aspect 2), from the second insertion portion side end of the first projection such as the drive side projections 94a and 94b to the first insertion side end of the second projection such as the driven side projection 95a The length L1 is shorter than the length L2 from the second rotary body side end of the hole of the first rotary body to the communication portion 84.
According to this, as described in the embodiment, the length from the second insertion-side end of the first projection such as the drive-side projections 94a and 94b to the second projection such as the driven-side projection 95a Compared to the connecting member 90 having a length L2 or more from the second rotary member side end of the hole of the drive side cylindrical portion 82a of the first rotary member such as the photosensitive gear 82 to the communication portion 84, L1 is The length of the connecting member can be shortened. As a result, the distance between the first rotating body such as the photosensitive gear 82 and the second rotating body such as the coupling member 41 can be reduced, and the axial length of the device can be shortened. Miniaturization can be achieved.

(Aspect 4)
In any one of (Aspect 1) to (Aspect 3), the groove portion contact portion that contacts the groove portion during driving transmission of the first protrusion portion such as the drive side protrusion portions 94a and 94b and the second protrusion portion such as the driven side protrusion portion 95a. But have a shape that protrudes in the rotational direction and extends straight in the radial direction.
According to this, as explained with reference to FIGS. 21 to 25 above, the rotational speed fluctuation can be suppressed.

(Aspect 5)
In any one of (Aspect 1) to (Aspect 4), each insertion portion 90a, 90b includes a spherical spherical portion (a driving-side spherical portion 91, a driven-side spherical portion 92), the axial direction is the X direction, and the X direction When a specific direction among the directions orthogonal to the Y direction is the Y direction, and the direction orthogonal to both the X direction and the Y direction is the Z direction, the spherical portion of each insertion portion is A circular portion (first drive side large circle portion 91a, a first driven side large circle portion 92a), and a large circle portion orthogonal to the Y direction of the ball (a third drive side large circle portion 91c, a third driven side large circle portion 92c) and a large circle portion (second drive side large circle portion 91b, second driven side large circle portion 92b) orthogonal to the Z direction of the ball, and it has a spherical shape with a thin wall.
According to this, as described with reference to FIG. 7, it is possible to suppress the sink of each insertion portion, and it is possible to mold each insertion portion with high accuracy. Further, the connecting member 90 can be molded using the first mold 391 moving in one direction (Y1 direction) and the second mold 392 moving in the opposite direction to the first mold 391, as shown in FIG. Compared to the configuration in which the inside of each insertion portion shown in 6 is thinned, the number of molds can be reduced. Moreover, even if the connection part of a connection member is long, each insertion part can be equally thinned. Thereby, even if the connection part of a connection member is long, the sink of each insertion part can be suppressed favorably, and each insertion part can be shape | molded accurately. In addition, the diameter of the connecting portion can be reduced compared to a configuration in which the inside of each insertion portion is thinned, and the connecting member can be reduced in size.

(Aspect 6)
In (Aspect 5), the connecting portion 93 is a cross-sectioned lightening portion 93a having a cross section having a straight portion extending in the Y direction and a straight portion extending in the Z direction, and a reinforcing portion having a rectangular cross section It was made into the shape alternately formed in the X direction.
According to this, as described in the embodiment, thinning of the connecting part can be performed using the first mold 391 and the second mold 392, and the sinking of the connecting part is suppressed. The connecting portion 93 can be accurately molded.

(Aspect 7)
In any of (Aspect 1) to (Aspect 6), there is provided a phase alignment means for adjusting the phase of the rotational direction of the first rotary body such as the photosensitive gear 82 and the second rotary body such as the coupling member 41.
According to this, as shown in the embodiment, the speed fluctuation of one rotation cycle of the first rotating body such as the photosensitive gear and the rotation of the photosensitive body mounted on the same shaft as the second rotation such as the coupling member The speed variation of the rotating body caused by the speed variation of one rotation period of the body can always be made the same. As a result, data acquisition for suppression control of the speed fluctuation of the rotary body (measurement of the speed fluctuation of one rotation of the rotary body using an encoder etc.) and data acquisition for color shift suppression control (patch pattern formed It is not necessary to carry out the detection of the degree of color shift by detecting the degree of color shift with an optical sensor every time the rotating body such as the photosensitive body is attached and detached, and the control of the apparatus can be simplified.

(Aspect 8)
In (aspect 7), the phasing means is a first phasing portion (in the present embodiment, the second drive side) for bringing the phases of the rotational directions of the front connecting member 90 and the first rotating body such as the photosensitive gear 82 into alignment. A projecting portion 94b and a second guide groove portion 86b), and a second phase matching portion for matching the phases of the connecting member 90 and the second rotating body such as the coupling member 41 (in this embodiment, the driven side spherical portion). 92 and the phase matching convex portion 144).
According to this, as shown in FIG. 14, the connecting member 90 is attached to the first rotating body such as the photoconductor gear 82 with a specified phase in the rotation direction. Then, a second rotating body such as the coupling member 41 is attached at a predetermined phase to the connecting member 90 attached to the first rotating body such as the photosensitive gear 82 at a predetermined phase. Thereby, the first rotating body and the second rotating body can be set to a prescribed phase via the connecting member 90.

(Aspect 9)
In (Aspect 8), at least one of the first phasing portion and the second phasing portion is provided in the insertion portion, and is provided with a phasing projection such as a second drive-side protrusion 94b that protrudes in the radial direction; The insertion portion such as the first insertion portion 90a having the phasing projection portion is provided in a hole portion such as the driving side cylindrical portion 82a of the rotating body such as the photosensitive gear 82 into which the insertion portion is inserted. And the phasing groove such as the second guide groove 86b into which the phasing protrusion is inserted when inserted into the portion, and the shape of the phasing protrusion is set to the first drive side protrusion 94a or the like Different from the shape of the projection, the phase of the phase matching groove is different from the shape of the groove such as the first guide groove 86a into which the projection is inserted when the insertion portion is inserted into the hole. Set the alignment protrusion to It was only inserted that can be configured in the groove for the cause.
According to this, as described in the embodiment, when the connecting member 90 and the rotating body such as the photosensitive member gear 82 are in the prescribed phase, the shape is different from the projecting portion such as the first driving side projecting portion 95a. The phasing protrusion such as the second drive side protrusion 94b can be inserted only into the phasing groove such as the second guide groove 86b, and the phasing of the coupling member 90 and the rotor can be matched to the prescribed phase. Can do.
In addition, "the shape is different" said here means that shapes or sizes are different (non-congruent).

(Aspect 10)
In (Aspect 8) or (Aspect 9), at least one of the first phasing portion and the second phasing portion is provided on the bottom surface of a hole such as the driven side hole 143 or the like, and projects in the axial direction A notch formed in the insertion portion so as not to be in contact with the projection when the projection such as the projection 144 and the insertion portion such as the driven spherical portion 92 are inserted into the hole. (The part where the third driven side large circle part 92c was cut).
According to this, when the rotating body such as the coupling member 41 and the connection member 90 are in a prescribed phase, the convex shaped portion such as the phasing convex portion 144 is the third of the insertion portion such as the driven spherical portion 92 or the like. The driven side large circle portion 92c enters a notch which is a cut portion, and an insertion portion such as the driven side spherical portion 92 of the connecting member 90 can be inserted into the hole of the rotating body, and the connecting member and the rotating body Can be connected.

(Aspect 11)
In any of (Aspect 1) to (Aspect 10), the first groove such as the drive groove 85 is a retaining portion that stops the first projection such as the drive projections 94a and 94b from coming off the first groove. The first insertion member has an opening at a position different from the position where the first groove is formed in the hole of the first rotary member such as the photosensitive gear 82, and has an opening extending in the axial direction. And a guide groove 86a, 86b for guiding the first projection into the hole when the 90a is inserted into the hole, and a communicating portion 84 for communicating the guide groove with the first groove; A control means such as a control projection 102 is provided which restricts one projection from moving from the first groove to the guide groove through the communication portion 84.
According to this, as described in the embodiment, the protrusions such as the drive side protrusions 94 a and 94 b inserted in the grooves such as the drive groove 85 pass through the communication portion 84 to form the drive groove 85 or the like. By moving from the groove to the guide groove 86a, 86b, it is possible to prevent the connecting member from coming off the rotating body such as the photosensitive gear.

(Aspect 12)
In any of (Aspect 1) to (Aspect 11), the connecting member 90 is axially movably attached to a first rotating body such as a photosensitive gear 82, and the connecting member 90 is a coupling member. A biasing means such as a coil spring 73 is provided to bias toward the second rotary body such as 41.
According to this, as described in the embodiment, when the second rotating body such as the coupling member 41 and the connecting member 90 are connected, the phase of the second rotating body and the connecting member in the rotational direction is matched. Even when the insertion portion such as the driven side spherical portion 92 is not inserted into the second rotary body, the connecting member 90 axially moves against the urging force of the urging means such as the coil spring 73 The rotating body such as a photosensitive body to which the second rotating body is attached can be attached to the apparatus main body. Then, when the drive is started, the connecting member is driven to rotate, and the connecting member and the second rotating body are in phase, the connecting member moves in the axial direction by the biasing force of the biasing means, and the second insertion portion 90b is inserted into the hole of the second rotary body, and the second rotary body and the connection member are drivingly connected, and the second rotary body can be rotationally driven.

(Aspect 13)
The image forming apparatus includes the drive transmission device according to any one of (Aspect 1) to (Aspect 12).
Accordingly, fluctuations in the rotational speed of the photosensitive drum 40 and the like transmitted by the drive transmission device can be suppressed, and a good image can be formed. In addition, the image forming apparatus can be miniaturized.

1b: back side plate 18: toner image forming unit 40: photosensitive drum 40a: drum shaft 41: coupling member 41a: shaft insertion portion 41b: driven side cylindrical portion 70: drive transmission device 73: coil spring 82: photoconductor Gear 82a: Drive-side cylindrical part 83: Drive-side hole 84: Communication part 85: Drive-side groove 85a: Retaining part 86a: First guide groove 86b: Second guide groove 87: Drive-side hole 90: Connection member 90a: first insertion part 90b: second insertion part 91: driving side spherical part 91a: first driving side great circle part 91b: second driving side great circle part 91c: third driving side great circle part 92: driven side spherical part Part 92a: First driven side large circle part 92b Second driven side large circle part 92c: Third driven side large circle part 93: Coupling part 93a: Lightening part 94a: First drive side projection part 94b: Second drive side Protrusions 95a: follower projections 96: spring retainers 1 00: bearing 101: cylindrical receiving portion 102: regulating projection 142: driven side groove 143: driven side hole 144: phase matching projection 190: connecting member 191: spherical portion 193: lightening portion 195: driven side projection Part 391: first mold 392: second mold 393: third mold 411: parallel pin 412: through hole O1: rotation center axis O2: rotation center axis θy: center angle

JP2013-195961A

Claims (13)

A first rotating body having a hole at the center of rotation;
A second rotating body having a hole at the center of rotation;
An axially extending first groove portion provided on an inner peripheral surface of the hole portion of the first rotating body;
An axially extending second groove provided on an inner peripheral surface of the hole of the second rotating body;
A radially inserted first projection inserted into the hole of the first rotating body, and a radially projected engagement with the second groove, the first projection having a radially protruding engagement engaged with the first groove A second insertion portion inserted into the hole of the second rotary body, and a connecting portion connecting the first insertion portion and the second insertion portion, A drive transmission device comprising: a connecting member connecting a rotating body and the second rotating body,
The first insertion portion is axially movable in the hole portion of the first rotating body;
The first protrusion can be inserted into the hole of the first rotating body at a position different from the formation position of the first groove in the rotational direction, and the position different from the formation position of the first groove in the rotational direction The first protrusion inserted into the hole in the hole can be located in the first groove inside the hole, and after being located in the first groove, the inside of the first groove toward the second rotary body The hole portion and the first groove portion of the first rotating body are configured to move the first projection portion,
The second maximum outer diameter of the insertion portion, the dynamic transmission drive characterized in that it is smaller than the inner diameter of the hole of the first rotating body. The drive transmission apparatus according to claim 1,
The first groove portion has a retaining portion that stops the first protruding portion from coming off from the first groove portion,
The hole of the first rotary body has an opening at a position different from the position where the first groove is formed in the rotational direction, and extends in the axial direction to insert the first insertion portion into the hole A drive transmission device comprising: a guide groove for guiding the first protrusion into the hole; and a communicating portion for communicating the guide groove with the first groove. The drive transmission device according to claim 2, wherein
The length from the second insertion portion side end portion of the first projection portion to the first insertion portion side end portion of the second projection portion is from the second rotation body side end portion of the hole portion of the first rotation body A drive transmission device characterized in that it is shorter than the length to the communication part. The drive transmission device according to any one of claims 1 to 3.
A drive transmission device characterized in that a groove contact portion that contacts the groove during drive transmission of the first protrusion and the second protrusion protrudes in the rotational direction and extends straight in the radial direction. The drive transmission device according to any one of claims 1 to 4.
Each insert comprises a spherical bulb,
Assuming that an axial direction is an X direction, and a specific direction of the directions orthogonal to the X direction is a Y direction, and a direction orthogonal to both the X direction and the Y direction is a Z direction.
The spherical portion of each insertion portion has a shape which is cut away leaving the great circle portion orthogonal to the X direction of the sphere, the great circle portion orthogonal to the Y direction of the sphere, and the great circle portion orthogonal to the Z direction of the sphere A drive transmission device characterized by the above. The drive transmission device according to claim 5, wherein
A cross-section cross-sectional light-cut portion consisting of a straight portion extending in the Y direction and a straight portion extending in the Z direction and a reinforcing portion having a rectangular cross section are alternately formed in the X direction. A drive transmission device characterized by having a shape. The drive transmission apparatus according to any one of claims 1 to 6.
A drive transmission device comprising phase adjusting means for adjusting a phase in a rotation direction between the first rotating body and the second rotating body. The drive transmission device according to claim 7, wherein
The phase alignment means includes a first phase alignment portion for adjusting the phase of the connection member and the first rotary body in the rotational direction, a second phase alignment portion for adjusting the phase of the connection member and the second rotary body, and A drive transmission device comprising: The drive transmission device according to claim 8, wherein
At least one of the first phasing portion and the second phasing portion is provided in the insertion portion for phasing, and is provided in the projection for phasing in the radial direction and the hole for phasing , the phase adjustment protrusion is composed of a phase adjustment groove portion to be inserted when inserted into the hole of the insertion portion according to the phase matching in the phase matching,
The shape of the phasing protrusion is made different from the shape of the first protrusion or the second protrusion of the insertion portion relating to the phasing , and the shape of the phasing groove is that of the hole relating to the phasing A drive transmission device characterized in that the phasing projection can be inserted only into the phasing groove, different from the shape of the first groove or the second groove . In the drive transmission device according to claim 8 or 9,
An axially projecting convex portion provided at a position shifted from the center of rotation of the bottom surface of the hole portion related to phase alignment, and at least one of the first phase alignment portion and the second phase alignment portion, and phase alignment The drive transmission device is characterized in that the insertion portion according to the present invention is constituted by the notch portion formed in the insertion portion according to the phasing so as not to be in contact with the convex shaped portion when inserted into the hole portion. . The drive transmission apparatus according to any one of claims 1 to 10.
The first groove portion has a retaining portion that stops the first protruding portion from slipping out of the first groove portion,
The hole of the first rotary body has an opening at a position different from the position where the first groove is formed in the rotational direction, and extends in the axial direction to insert the first insertion portion into the hole A guide groove for guiding the first protrusion into the hole, and a communication part for communicating the guide groove with the first groove,
A drive transmission device, comprising: a restricting means for restricting the movement of the first projection from the first groove to the guide groove through the communication part. The drive transmission apparatus according to any one of claims 1 to 11.
The connecting member is axially movably attached to the first rotating body,
A drive transmission device comprising biasing means for biasing the connecting member toward the second rotating body. An image forming apparatus having a drive transmission device according to any one of claims 1 to 12.

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